1. Field of the Invention
With regard to the classification of art, this invention is believed to be found in the general class entitled "Valves and Valve Actuation" and more particularly to those subclasses pertaining to rotary butterfly valves.
2. Description of Related Art
Butterfly valves are known in the prior art. One example of prior art is U.S. Pat. No. 5,236,003 which issued to Habicht on Aug. 17, 1993. U.S. Pat. No. 5,236,003 is solely owned by the present inventor.
U.S. Pat. No. 5,236,003 has been successfully used in many material handling applications. This cited prior art patent is primarily used with small hoppers or funnels which have limited capacity. The quick coupling and modular design has resulted in that valve being used at the discharge or feed end of large hoppers and the like. It has been found that the self-centering features of U.S. Pat. No. 5,236,003 has at least one disadvantage when used with heavy loads. That disadvantage allows the disc member to be displaced in a direction which is parallel to the flow of material. For example: If the load being supported by the disc is very heavy, the disc member is displaced downward. This downward shifting of the disc member has been found to mar the surface of the valve seat when the disc member is rotated.
While it is easy to replace the valve seat in the cited prior art, it is not always desirable. Therefore, it has been determined that an improvement to the cited prior art was necessary, This improvement should retain the self-centering properties of the cited prior art while increasing its load carrying ability.
The present invention solves the identified need as described above.